GCF (HCF) of 81 and 108

"Greatest Common Factor" Calculator
Greatest Common Factor of
and

What is the Greatest Common Divisor of 81 and 108?

Answer

GCF (HCF) of 81 and 108 is
27

Common factors: 1, 3, 9, 27

27 divides both: 81 ÷ 27 = 3, 108 ÷ 27 = 4 — and 3 and 4 share no factor but 1, so no larger number divides both.

81 = 34

108 = 22 × 33

Prime81108Lowest power
2—22—
3343333

— = power 0: the prime is not a factor of this number, so it cannot be in the GCF.

GCF = 33 = 27

More with these numbers

Related Calculations

See Also

GCF Table

Number 1Number 2GCF
81933
81941
81951
81963
81971
81981
81999
811001
811011
811023
811031
811041
811053
811061
811071
8110827
811091
811101
811113
811121
811131
811143
811151
811161
811179
811181
811191
811203
811211
811221

FAQ

What is the Greatest Common Divisor of 81 and 108?

GCF (HCF) of 81 and 108 is 27

How to find the GCF of 81 and 108?

You can find the GCF of 81 and 108 by listing all factors of both numbers and picking the greatest common one, or by prime factorization. The GCF of 81 and 108 is 27.

What prime factors do 81 and 108 share?

The prime factorizations of 81 and 108 have 3 × 3 × 3 in common, and multiplying those shared primes gives 27 — exactly the greatest common factor.

How does the GCF reduce the fraction 81/108?

Divide the numerator and the denominator by the GCF 27: 81 ÷ 27 = 3 and 108 ÷ 27 = 4. So 81/108 in lowest terms is 3/4.

See Also